BackPressureBarrier

simple module

Prevents backpressure propagation from its output to its input and vice versa. It always allows pushing and pulling packets independently of what the connected modules would allow to do in their current state. Both pushed and pulled packets pass through unchanged, but the operations may raise a runtime error due to this module preventing backpressure propagation.

Inheritance diagram

The following diagram shows inheritance relationships for this type. Unresolved types are missing from the diagram.

Used in compound modules

Name	Type	Description
Ieee8021qFilter	compound module	Implements the IEEE 802.1Q per-stream filtering and policing. The relationship between streams, gates, and meters is not one-to-one. The number of streams, gates, and meters can be different, and the module will take care of the connections between the submodules based on the `streamFilterTable` parameter.
SimpleIeee8021qFilter	compound module	Implements a simplified version of the IEEE 802.1Q per-stream filtering and policing. Each filtered stream has its own path where metering and filtering happens independently of any other stream.

Extends

Name	Type	Description
PacketFlowBase	simple module	Base module for various packet flow modules. A packet flow module passes or streams all pushed or pulled packets after processing them from its input to its output.

Parameters

Name	Type	Default value	Description
displayStringTextFormat	string	"passed %p pk (%l)"	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information

Properties

Name	Value	Description
class	BackPressureBarrier
display	i=block/segm

Gates

Name	Direction	Size	Description
in	input
out	output

Signals

Name	Type	Unit	Description
packetPushedIn	inet::Packet
packetPulledIn	inet::Packet
packetPushedOut	inet::Packet
packetPulledOut	inet::Packet

Statistics

Name	Title	Source	Record	Unit	Interpolation Mode	Description
flowIncomingDataRate	flow specific incoming data rate	throughput(demuxFlow(merge(packetPushedIn, packetPulledIn)))	vector	bps	linear	the statistical value is the flow specific data rate of the incoming packets
outgoingDataRate	outgoing data rate	throughput(merge(packetPushedOut, packetPulledOut))	vector	bps	linear	the statistical value is the data rate of the outgoing packets
incomingDataRate	incoming data rate	throughput(merge(packetPushedIn, packetPulledIn))	vector	bps	linear	the statistical value is the data rate of the incoming packets
outgoingPacketLengths	outgoing packet lengths	packetLength(merge(packetPushedOut, packetPulledOut))	sum, histogram, vector	b	none	the statistical value is the length of the outgoing packet
flowIncomingPacketLengths	flow specific incoming packet lengths	packetLength(demuxFlow(merge(packetPushedIn, packetPulledIn)))	sum, histogram, vector	b	none	the statistical value is the flow specific length of the incoming packet
flowOutgoingDataRate	flow specific outgoing data rate	throughput(demuxFlow(merge(packetPushedOut, packetPulledOut)))	vector	bps	linear	the statistical value is the flow specific data rate of the outgoing packets
incomingPacketLengths	incoming packet lengths	packetLength(merge(packetPushedIn, packetPulledIn))	sum, histogram, vector	b	none	the statistical value is the length of the incoming packet
flowOutgoingPacketLengths	flow specific outgoing packet lengths	packetLength(demuxFlow(merge(packetPushedOut, packetPulledOut)))	sum, histogram, vector	b	none	the statistical value is the flow specific length of the outgoing packet
incomingPackets	incoming packets	merge(packetPushedIn, packetPulledIn)	count	pk		the statistical value is the incoming packet
outgoingPackets	outgoing packets	merge(packetPushedOut, packetPulledOut)	count	pk		the statistical value is the outgoing packet

Source code

//
// Prevents backpressure propagation from its output to its input
// and vice versa. It always allows pushing and pulling packets independently
// of what the connected modules would allow to do in their current state. Both
// pushed and pulled packets pass through unchanged, but the operations may raise
// a runtime error due to this module preventing backpressure propagation.
//
simple BackPressureBarrier extends PacketFlowBase
{
    parameters:
        displayStringTextFormat = default("passed %p pk (%l)");
        @class(BackPressureBarrier);
        @display("i=block/segm");
}

File: src/inet/queueing/common/BackPressureBarrier.ned